Hi guys I just bought an 91 acura nsx yesterday. Its completely stock except hid and exhaust. I drove it for 100 miles and everything was fine (drove it home). Okay I have taken the car to day upto 140 mph on the freeway, it was fine then. but when I was driving around town my check engine light came on now I've check the fluids, there fine. Started it up no engine light ?!? rev it alittle my car idles at 1grand, rev it again it went down to 500rpm then came up the down again to 600rpm, so I'm thinking it might be a 02 sensor or intake sensor. so I thought it was fine until I drove it to my office the light came back on but the car drives normal what can it be????